How is HIV diagnosed in an infant?

HIV is diagnosed in adults through antibody or combination antigen/antibody screening tests. However, we do not use this test in infants due to the presence of the birth parent's antibodies in the infant's blood. A DNA PCR (polymerase chain reaction) test is used to detect particles of the virus in the baby’s blood. These tests are usually performed at different intervals, generally recommended at birth, two weeks, two months and 4 months. However, different institutions have other testing schedules. The guidelines indicate that two negative PCR test results are needed to confirm a baby as non-infected with HIV (one before and one after 4 months). Antibody testing is conducted on infants between 12 and 18 months to document the clearance of the birth parent's antibodies. If you are unsure about the best schedule for testing, please call the Illinois Perinatal HIV Hotline at 1-800-439-4079.